The present invention relates to labeling machines, particularly to a station for checking and verifying labels, specially auto adhesive ones.
Traditional labeling machines apply labels to articles of different kind, e.g. bottles and/or vials, previously sealed. The labels precisely describe the product contained in the bottles or vials, giving basic information about the product, such as the product composition, packaging date and expiry date, etc.
The bottles and/or vials are kept in magazines situated upstream of the labeling machine and are collected downstream thereof by suitable conveying means.
Each labeling machine is equipped with a device, which checks both the type and the presence of the label by a contemporary check of printing and bar code on the same.
Consequently, when the check device detects a missing or defective label, the corresponding bottle and/or vial is rejected downstream of the machine, with or without the defective label having been applied.
When the device detects a missing label on the label carrying band, the related rejected bottle and/or vial can be collected, so as to be recycled into the machine process.
The economic advantage depends strictly on the type of product contained in the bottle and/or vial.
When the device detects a defective label, the rejected bottle and/or vial cannot be recovered, and consequently, it cannot be recycled into the machine process.
This is impossible due to too much labor needed to remove the non suitable label from the relative bottle and/or vial, as well as to a strong possibility of confusion about the precise content of the bottle and/or vial.
The object of the present invention is to propose a check station for labels, in particular auto adhesive labels, for a labeling machine, which detects defective labels and withdraws them from the relative carrying band, so as to allow a complete recycling of the rejected articles.
Another object of the present invention is to propose a station obtained by a simple, cheap, extremely reliable and practical technical solution, which optimizes the working cycle of the labeling machine.
The above mentioned objects are obtained, in accordance with the claims, by a station for checking labels, in particular auto adhesive labels, in a labeling machine, said station co-operating with a first sensor, located upstream of the station for checking the presence of said labels, and with a check group, also located upstream for verifying the acceptability of said labels, and with a second sensor, located downstream of said station for checking again the presence of said labels, with said sensors and check group being connected to a station control unit, and with said labels being attached to a band driven upstream and downstream of said station in accordance with a same forward direction, said labels check station further including:
a working group capable of removing damaged labels from said band, said working group including a operative roller, having vertical axis and idling on an axle, supported by a base contained with a clearance within a related cylindrical shaped windowed casing which is freely supported by said axle of said operative roller, said windowed casing featuring at one side a vertical plate having an upstream edge and a downstream edge, said operative roller and vertical plate delimiting an interspace through which said band passes while resting on said operative roller;
a tightening roller, idling on an axis, carried by said base for guiding said belt, said tightening roller co-operating with said working group and being located downstream of said working group with respect to said forward direction of said band;
one collecting group supported by the same base and co-operating with said working group for collecting defective auto-adhesive labels removed from said band by said working group;
said windowed casing being operated on command of said control unit, in phase relation with the detection of a defective label, by said check group with the aid of a related actuator means, from a rest configuration, in which the related plate is substantially parallel to said forward direction, with the band completely guided by said operative roller and tightening roller, to a working configuration, in which said plate is substantially perpendicular to said forward direction, with the band engaged by said downstream edge of said plate so as to remove said defective label due to the sharp variation of the tangent of the band trajectory.